In a cast iron skillet or dutch oven, fill with oil to the depth of one to two inches. Place over medium-high heat, and bring oil up to 350*. Place flour, beaten eggs and panko bread crumbs in separate shallow bowls.Peel and cut avocados into 1/4 inch thick slices. Working with a few at a time, dredge the slices in the flour, then the eggs. Then toss them in the panko bread crumbs, pressing the bread crumbs so they stick to the avocado slices. Put slices into the frying oil, and cook until browned and crispy, about one to two minutes. When you take them out of the oil, place them on a paper towel lined plate and sprinkle with salt. Serve immediately with spicy mayo.